MetService has issued a Severe Weather Warning for New Zealand.

Periods of heavy snow are expected today and possible heavy rain on Monday for the southern South Island.

There are also possible severe gales west to southwesterlies for parts of New Zealand.

"A cold strong southwest flow is affecting New Zealand," says a MetService spokesperson.

"Several troughs embedded in this flow are bringing snow to low levels over the southern South Island today and possible heavy rain there on Monday, with strong west to southwesterly winds expected to affect many areas."

Heavy Snow Warnings remain in force for southern parts of the South Island, while a Heavy Rain Watch is now in force for Clutha and Southland. Strong Wind Watches are now in place for many parts of New Zealand.

A Heavy Snow Warning is in place for the following two areas:

Area: Fiordland about and south of Doubtful Sound
Valid: 13 hours from 9:00am Sun 2 Jul to 10:00pm Sun 2 Jul
Forecast: Periods of heavy snow. Expect a further 15 to 20 cm to accumulate above 300 metres on top of what has already fallen, with lesser amounts down to 100 metres.

Area: Otago south of line from Queenstown to Alexandra and to Mosgiel, also Southland and Stewart Island
Valid: 16 hours from 9:00am Sun 2 Jul to 1:00am Mon 3 Jul
Forecast: Periods of heavy snow. Expect a further 15 to 20 cm to accumulate above 300 metres on top of what has already fallen, with lesser amounts down to 100 metres.

Heavy snow may disrupt travel in affected areas and could damage trees and powerlines. Cold conditions may cause stress for livestock.

A Heavy Rain Watch is in place for these areas:

A Heavy Rain Watch is now in force for Clutha and Southland. This is valid for 15 hours from 3am -6pm Monday July 3. Periods of heavy rain are expecetd. Rainfall amounts may approach warning criteria, especially about the mountains north of Mossburn to Riversdale and Balclutha.

A Strong Wind Watch is in place for these areas:
Area: Northland, Auckland, Great Barrier Island, Waikato, Waitomo, Coromandel Peninsula, and Bay of Plenty west of Whakatane
Valid: 6 hours from 3:00pm Mon 3 Jul to 9:00pm Mon 3 Jul
Forecast: West to southwest winds may approach severe gale in exposed places.

Area: Taranaki, Taumarunui, Taupo, Taihape, Whanganui, Manawatu, the Tararua District, and Hawkes Bay about and south of State Highway 5.
Valid: 7 hours from 12:00pm Mon 3 Jul to 7:00pm Mon 3 Jul
Forecast: West to southwest winds may approach severe gale in exposed places.

Area: Marlborough south of Blenheim
Valid: 18 hours from 3:00am Mon 3 Jul to 9:00pm Mon 3 Jul
Forecast: Another period of strong winds is expected for a time on Monday, when west to southwest winds may approach severe gale in exposed places.

Area: Nelson
Valid: 12 hours from 6:00am Mon 3 Jul to 6:00pm Mon 3 Jul
Forecast: Another period of strong winds is expected for a time on Monday, when west to southwest winds may approach severe gale in exposed places.

Area: Fiordland, Southland, Stewart Island, Clutha and Dunedin
Valid: 10 hours from 4:00am Mon 3 Jul to 2:00pm Mon 3 Jul
Forecast: Another period of strong winds is expected for a time on Monday, when west to southwest winds may approach severe gale in exposed places.